[PATCH] nios2: Don't disable relaxation with --gdwarf-N

["H.J. Lu" <hjl.tools@gmail.com>]

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On Mon, Jan 25, 2021 at 1:19 PM H.J. Lu <hjl.tools@gmail.com> wrote:
>
> After
>
> commit 705989f19adf20dd70c50237ec61cd708f2b0939
> Author: H.J. Lu <hjl.tools@gmail.com>
> Date:   Mon Jan 18 06:25:05 2021 -0800
>
>     as: Automatically enable DWARF5 support
>
> --gdwarf-5 is no longer needed to accept DWARF5 info generated by GCC.
>
> Since assembler generated debug information is incompatible with
> relaxation, don't generate debug information for assembly codes with
> --gdwarf-5 which is passed down by GCC.
>
> OK for master and 2.36 branch?
>
> H.J.
> ---
>         PR gas/27243
>         * config/tc-nios2.c (md_begin): Set debug_type to DEBUG_UNSPECIFIED
>         for --gdwarf-5.
>         * testsuite/gas/nios2/relax.d: New file.
>         * testsuite/gas/nios2/relax.s: Likewise.

GCC 11 passes --gdwarf-5 to assembler to enable DWARF5 debug info.  Don't
disable relaxation when --gdwarf-N is specified.  The assembler generated
debug information will treat the sequence of the relaxed instructions as
a single instruction.

OK for master and 2.36 branch?

-- 
H.J.

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From d39a3002bdec4e71fa6f68b505c9cb0579821776 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Mon, 25 Jan 2021 13:14:34 -0800
Subject: [PATCH] nios2: Don't disable relaxation with --gdwarf-N

GCC 11 passes --gdwarf-5 to assembler to enable DWARF5 debug info.  Don't
disable relaxation when --gdwarf-N is specified.  The assembler generated
debug information will treat the sequence of the relaxed instructions as
a single instruction.

	PR gas/27243
	* config/tc-nios2.c (md_begin): Don't disable relaxation with
	--gdwarf-N.
	* testsuite/gas/nios2/relax.d: New file.
	* testsuite/gas/nios2/relax.s: Likewise.
---
 gas/config/tc-nios2.c           |  4 ----
 gas/testsuite/gas/nios2/relax.d | 25 +++++++++++++++++++++++++
 gas/testsuite/gas/nios2/relax.s |  5 +++++
 3 files changed, 30 insertions(+), 4 deletions(-)
 create mode 100644 gas/testsuite/gas/nios2/relax.d
 create mode 100644 gas/testsuite/gas/nios2/relax.s

diff --git a/gas/config/tc-nios2.c b/gas/config/tc-nios2.c
index eea6687fcc4..be4536caa8a 100644
--- a/gas/config/tc-nios2.c
+++ b/gas/config/tc-nios2.c
@@ -3643,10 +3643,6 @@ md_begin (void)
   nios2_as_options.noat = FALSE;
   nios2_as_options.nobreak = FALSE;
 
-  /* Debug information is incompatible with relaxation.  */
-  if (debug_type != DEBUG_UNSPECIFIED)
-    nios2_as_options.relax = relax_none;
-
   /* Initialize the alignment data.  */
   nios2_current_align_seg = now_seg;
   nios2_last_label = NULL;
diff --git a/gas/testsuite/gas/nios2/relax.d b/gas/testsuite/gas/nios2/relax.d
new file mode 100644
index 00000000000..ca01a4f926a
--- /dev/null
+++ b/gas/testsuite/gas/nios2/relax.d
@@ -0,0 +1,25 @@
+#source: relax.s
+#as: --gdwarf-5
+#objdump: -w -WL -dr --prefix-addresses --show-raw-insn
+#name: NIOS2 relax with --gdwarf-5
+
+# Test relaxation with assembler generated debug info.
+.*:     file format elf32-littlenios2
+
+Contents of the .debug_line section:
+
+CU: ./relax.s:
+File +name +Line +number +Starting +address +View +Stmt
+relax.s +2 +0 +x
+relax.s +5 +0x10018 +x
+relax.s +- +0x1001c
+
+Disassembly of section .text:
+0x00000000 21400526 	beq	r4,r5,0x00000018
+0x00000004 0002e03a 	nextpc	at
+0x00000008 085fffc4 	addi	at,at,32767
+0x0000000c 085fffc4 	addi	at,at,32767
+0x00000010 08400484 	addi	at,at,18
+0x00000014 0800683a 	jmp	at
+	...
+0x00010018 f800283a 	ret
diff --git a/gas/testsuite/gas/nios2/relax.s b/gas/testsuite/gas/nios2/relax.s
new file mode 100644
index 00000000000..ef417fdc33b
--- /dev/null
+++ b/gas/testsuite/gas/nios2/relax.s
@@ -0,0 +1,5 @@
+	.text
+	bne	r4, r5, 1f
+	.zero 0x10000
+1:
+	ret
-- 
2.29.2